Two particles of mass 5 kg and 10 kg respectively are attached to the two ends of a rigid rod of length 1 m with negligible mass. the centre of mass of the system from the 5 kg particle is nearly at a distance of :

Options

A. 33cm
B. 50cm
C. 67cm
D. 80cm

Answer

C

Explanation

`x_(cm)= (m_(1) x_(1) + m_(2) x_(2))/(m_(1) + m_(2))`
`= (5 xx 0 + 100 xx 10)/(5 + 10) = (200)/(3) = 66.66 cm`
`x_(cm) ~= 67 cm`
Aliter :

mr = constant `rArr prop (1)/(m)`
`(r_(1))/(r_(2))= (m_(2))/(m_(1))= (10)/(5) = (2)/(1)`
`r_(1)= (2)/(3) r= (2)/(3) xx 1m`
`= (2)/(3) xx 100cm= 66.66cm ~= 67cm`